( -^'ö-t ) 



Since Makchi sliited, tlial after large lesions as hemi-exstirpation 

 of the ceiebellmn a iiiiniber of 'nerve-strands degenerate np to the 

 meseneepiialon and down to the spinal cord, it is notable, that subse- 

 quently Mahaim, Fkrrikr and Tlrnkr, R. Russell, Thomas and 

 especially Probst and van Gehichten have more and more directed 

 their attention lo smaller and smaller lesions, so that it became 

 more and more clear, that most of the degenerations, found l\y Marchi, 

 were caused by affection of neighbouring parts. Finally have Clarke 

 and HoRSLEY recently succeeded in stating definitely, that all fibres of 

 the superior crus cerebelli do not arise from the cortex, but from 

 the basal nnclei. Their material was larger than that of any of the 

 precedent investigators and only very limited exstirpations, mostly 

 without any lesion of the nuclei, were used. If the lesion was 

 limited and the cerebellar cortex exclusively hurt, never the dege- 

 neration was found further than the nuclei. Tliey stated moreover, 

 which parts of the cortex are directly connected with s[iocial parts 

 of the basal nuclei. 



Independently of this result the examination of my own material 

 (experiments on the lobus petrosus in different rodentia) tends clearly 

 to reinforce tlieir conclusion. Whereas in the case of the squirrel (where 

 only cortical and white matter in tlie lobus petrosus cerebelli -- inex- 

 actly called flocculus — can be iiurt) the degeneration stops short in 

 the lateral part of the dentate nucleus, we find in the rabbit always 

 a part — especially and exclusively the middle third part of the 

 superior crus cei'ebelli on cross section — degenerated. These dege- 

 nerated fibres could be followed in (he series of sections up to the 

 lesion. Here, in th(? case of the rabiiit, we had removed a number of 

 ganglioncells, situated in (lie pe<luncle of the lobus petrosus and 

 being contiguous to the Jiuclcus deiitatus. 



We see therefore that as well the MAHCHi-\Aork in the same spe- 

 cies as experiments in kin ajiiuial groups lead to the same 

 answer to our question viz. that only the ganglioncells of the basal 

 nuclei and not (he cells of Pirkin.t?;, have to be regarded as the 

 origin of the degenerations after (lie cerebellar lesion. The last reserve 

 left in this matter by Er)iN(iKK can therefore, so it appears to me, 

 be abandoned. 



In accordance with the above investigators and also with my 

 former communication in These Proc. VII p. 202 about experi- 

 ments in rabbits 1 could not find in the spinal cord of (he 

 squirrels, examined, any degeneration. Regarding the middle cere- 

 bellar peduncle, the relations are more complicated and need further 

 research. 



